@PitaJ Oh, I got it. But I tried and unfortunately it does not change the attribute.
Plus, I found the value is the length of placeholder 's length. the default English placeholder is "Enter tags here, between 3 and 24 characters each.", that's why it is 50.
I am using zh-CN, according to translation, it is 23 characters, so value is 23.
However, one character Chinese is 2 English letter wide, to show the placeholder full, the value need to be 46.
Can you fix it? thanks.